Hair Straightening Apparatus

ABSTRACT

An improved hair iron for straightening or styling hair is presented. The hair iron comprises two arms pivotally connected at one end and includes a biasing spring near the pivot and connected to arms to bias the arms in a normally open position. Included on one arm is a positive temperature coefficient (“PTC”) heater with a tourmaline coating on the heating surface. Inclusion of a single heating surface on only one arm reduces the risk of heat damage to the hair-to-be-styled and likewise reduces the iron&#39;s energy consumption. Included on the other, non-heated, arm is a compressible element for gripping the hair-to-be-styled. The compressible element minimizes the risk of damage to the hair from potential over-compression of the arms of the iron by the stylist. Consequently, the fullness or volume of the styled hair is increased.

FIELD OF THE INVENTION

The present invention relates generally to the field of hairstraightening devices or hair irons, and in particular, to an improvedhair straightening device that causes less damage to hair and is moreenergy efficient. The improved hair straightening device is suitable foruse in beauty salons, barber shops, and homes.

BACKGROUND OF THE INVENTION

Many types of hair straightening devices (also referred to as hairirons) are presently available for commercial sale. Prior art hair ironstypically comprise two arms connected by a pivot and a biasing spring atone end. The spring biases the arms into an open rest position at theirfree ends. The free end of each arm is typically equipped with a heatingelement having a metal and/or ceramic surface for applying heat to thehair-to-be-styled or straightened. By pressing on the arms of a hairiron, a stylist may move the two arms towards one another through avariable angle to bring the heating surfaces into contact with eachother, or with the hair-to-be-styled. The hair-to-be-styled is placedbetween the heating elements and is either gripped and drawn between thearms, or the arms are moved down the length of the hair shafts. The hairis straightened as a result of the heat and pressure that is applied tothe hair. In instances where the hair is wet when the hair iron isapplied, the heating surfaces are typically sufficiently hot to flashthe water present in the hair to steam, which enhances the straighteningprocess.

One drawback to the use of conventional hair irons is the risk ofdamaging the hair upon exposure to the heat and pressure applied to thehair during styling. For example, the heating elements of common hairirons are typically composed of metal and/or ceramic and their heatingsurfaces and may be heated to a relatively high temperature, i.e. up toabout 500 degrees Fahrenheit. Hair in direct contact with the two heatedsurfaces common to prior art hair irons can be rapidly heated toexcessive temperatures which may in some instances lead to scorching ofthe hair, or other heat related damage.

In addition, the metal and/or ceramic materials from which the heatingsurfaces are typically made are relatively hard and unyielding. When thehair to by styled is gripped between two hard heating surfaces, it isall too easy for a stylist to apply excess pressure and in so doingcrush the hair or inflict other physical damage to the hair such askinks, undesired bends, split ends, and the like. Hair can also beflattened by the excess heat and pressure generated by prior art hairirons. All of the aforementioned types of damage sharply reduce thepleasing appearance of the hair and consequently defeats the purpose ofhaving hair styled.

There is, thus, a need in the hair styling art for an improved hair ironthat is . less likely to inflict damage upon the hair being styled. Suchan improved iron would reduce damage to the hair by subjecting the hairto less heat and thereby reduce the risk of scorching. Such an improvedhair iron should also reduce the risk of hair damage caused by heatand/or pressure on the hair by providing one of the free ends of theiron with a compressible surface so as to reduce the risk of crushing,kinking, flattening, or bending the hair, and of causing split ends. Itwould also be desirable for such an improved hair iron to reduce energyconsumption over that of prior art hair irons.

SUMMARY OF THE INVENTION

The present invention hair iron solves the problems associated withprior art hair irons by equipping only one of the two arms of the hairiron with a heating element, unlike prior art hair irons which useheating elements on both arms. The non-heated arm of the new hair ironis equipped with a compressible element. By equipping only one arm witha heating element, the present invention hair iron reduces the heat loadapplied to the hair to be styled, and therein significantly reduces therisk of scorching, flattening, or other heat related damage. By reducingheat related damage, the present invention hair iron allows the hair toretain volume. Energy consumption is also significantly reduced.

By equipping one arm of the iron with a compressible element rather thana second heating element, the new iron substantially reduces thelikelihood of damage to the hair-to-be-styled which often occurs due tostylists exerting too much force on the arms of the iron and therebyapply excessive pressure and over-compress the hair. By reducing thelikelihood of hair damage due to over-compression, the present inventionallows the hair to retain fullness, i.e. volume. Achieving a reductionin the amount of bent, crushed, flattened, or kinked hair, as well assplit ends, provides a substantial improvement over prior art irons. Thecompressible element on the non-heated arm of the iron may also includea textured surface that aids in maintaining the fullness of thehair-to-be-styled. Additional features such as a tourmaline-compositioncoating on the heating surface and a positive temperature coefficient(“PTC”) heater with variable heat output and automatic shut-off are alsoprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hair iron in accordance with theprinciples of the present invention, shown in the normally openposition.

FIG. 2 is a side view of the hair iron shown in FIG. 1.

FIG. 3 is an enlarged perspective view, partially cutaway, of the anembodiment compressible element of the hair iron of FIG. 1.

FIG. 4 is a perspective view of the hair iron of FIG. 1, shown in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 through 3, the present invention comprises ahair iron 10 having an upper (or first) arm 12 and a lower (or second)arm 14. The upper and lower arms 12 and 14 are pivotally connected atone end by a pivot 16. The ends of the upper and lower arms 12 and 14opposite the pivotally connected ends are free ends. The upper and lowerarms 12 and 14 are able to open and close via rotation of theconstrained ends about the pivot 16. A biasing spring 18 (not shown) islocated adjacent to the pivot 16 and connected to the arms 12 and 14such that the spring 18 biases the arms into a normally open position atan acute angle when at rest. By squeezing the arms, a stylist may causethe arms 12 and 14 to move to a closed position in which the arms aresubstantially parallel to one another. References herein to “upper” and“lower” arms are used for convenience only and are not intended to limitthe orientation of the device set forth herein.

The upper and lower arms 12 and 14 comprise upper and lower grippingportions 20 and 22, respectively, which are disposed near the pivot 16.The gripping portions 20 and 22 allow the stylist to grip and manipulatethe hair iron 10. The gripping portions 20 and 22 may optionally beequipped with a textured or contoured surface (not shown) to assist inpreventing slippage of the hair iron in a stylist's hand. The upper andlower arms 12 and 14 further include upper and lower hair treatmentportions 24 and 26, respectively, which are disposed adjacent the freeends of the arms. The upper hair treatment portion 24 includes a heatingelement 28 which includes a substantially flat, hair-contacting heatingsurface 30 (best shown in FIG. 2). An electrical cord 32 is disposedwithin the upper arm 12 and is in electrical connection with the heatingelement 28. The lower treatment portion 26 of the lower arm 14 includesa compressible element 34, which may be a pad or similar compressiblematerial, and which has a hair-contacting portion 33.

The compressible element 34 protects the hair-to-be-styled 42 (shown inFIG. 4) from physical damage. In comparison to the hard, rigid surfaceof a ceramic or metallic heating element, the compressible element 34yields and thereby diminishes the compressive force applied to the hairby the stylist when squeezing the arms 12 and 14 of the hair iron 10against the hair 42. By diminishing or relieving the compressive forceapplied to the hair, the compressible element 34 tends to increase thefullness, i.e. volume, of the hair-to-be-styled. The compressibleelement 34 also allows a degree of lateral movement of the hair alongthe surface of the element which also aids in reducing physical damageto the hair 42.

The compressible element 34 may optionally include a pattern 36 ofalternating peaks 38 and valleys 40, or more generally, alternatingraised and lowered surfaces. Such a pattern tends to further reduce therisk of damage to the hair 42 by over-compression of the arms 12 and 14of the iron 10 and provides a further degree of lateral movement betweenthe hair and the element, i.e. the hair can slide between thealternating surfaces of the element. A depth of about 0.05 to about0.100 inches between the peaks and valleys of the alternating surfaceshas been found to be suitable. Other depths may also be suitable.Suitable patterns for the alternating peaks and valley include, withoutlimitation, repeating squares, rectangles, and triangles, among others.In other embodiments, the compressible element 34 may have asubstantially flat hair-contacting surface 33 rather than one ofalternating peaks and valleys.

The upper and lower arms 12 and 14 may be made of any suitable material.Various ceramic, plastic, and metallic materials are suitable and areknown in the art. In one embodiment the arms 12 and 14 are made fromheat resistant plastic.

The heating surface 30 of the heating element 28 is generallyrectangular in shape. In one embodiment of the hair iron 10, the heatingelement comprises multiple elements consisting of one inch squaresurfaces or plates. The heating elements or plates may optionally be“floating plates,” i.e. plates that allow for some lateral and downwardmovement into the upper arm 12, which may further reduce the incidenceof hair damage caused by heat and pressure applied to the hair. Theheating element automatically shuts off after a predetermined period ofnonuse. The heating element temperature can be made adjustable from aminimum temperature of zero degrees to a maximum temperature of about450 degrees Fahrenheit. Optionally, the present invention hair iron 10may include a universal voltage feature, i.e. the iron 10 may beequipped with circuitry to allow the iron to operate from eitherdomestic 110 volt AC current or 220 volt AC current as is common outsideof the United States.

Multiple types of heating elements are suitable for use in the presentinvention and are known in the art. However, positive temperaturecoefficient (“PTC”) heaters are preferred. PTC heaters are composed ofceramic materials and are noteworthy because they exhibit low electricalresistance at ambient temperature and then gradually increase inresistance as they are heated by electric current passing through theunit. PTC heaters also exhibit a large increase in electrical resistanceupon reaching their maximum temperature which in turn causes currentflow to be greatly reduced. Consequently, PTC heaters can maintainequilibrium at their maximum operating temperature while drawing acomparatively small steady state current. A PTC heater's maximumoperating temperature is a function of material composition. PTC heatersare advantageous because they provide a large amount of heat while beingself-regulating, and hence, are well suited for use in the presentinvention. One non-limiting example of the internal construction of asuitable PTC heater is disclosed in U.S. Pat. No. 3,996,447.

The heating surface 30 of the heating element 28 may optionally beequipped with a surface coating 48 (best shown in FIG. 2) comprising, atleast in part, the mineral tourmaline. Methods of deposition oftourmaline coatings upon ceramic, plastic, and metallic substrates areknown in the art. Tourmaline, also known as complex aluminumborosilicate, has been adapted to hair styling tools because whenheated, the material exhibits pyroelectricity. Pyroelectricity is theability of certain materials to generate a temporary electricalpotential when they are heated or cooled. When heated, tourmaline isbelieved to emit negatively charged ions. It is believed within the hairstyling industry that these negatively charged ions help smooth hair bysealing the cuticles, and by assisting in the retention of moisture. Theeffects of heated tourmaline are believed to make hair appear smoother,shinier and healthier. Tourmaline coatings also typically result in asmoother surface than ceramic. Consequently, less friction is producedas hair is pulled through the tool, resulting in less damage to thehair.

The compressible element 34 of the present invention may be made fromany material which can withstand temperatures of up to about 450 degreesFahrenheit. Several cloth materials are suitable and are known in theart. One suitable material is polytetrafluoroethylene (“PTFE”). PTFE iscommercially available from EI Dupont de Nemours and Company (“Dupont”)under the Teflon brand. The compressible element 34 may also beconstructed from aramid fibers which are commercially available fromDupont under the Kevlar and Nomex brands. Suitable fabrics comprising ablend of one or more of the above materials and other materials are alsoknown in the art.

Operation of the Invention

Referring now to FIGS. 1-4, in operation, a stylist will first turn onthe heater 28 of the present invention hair iron 10. (The hair iron 10will typically be equipped with an on/off switch as is known in theart.) When the exposed exterior hair-contacting surface 30 of theheating element 28 reaches the desired temperature, the stylist thenplaces the hair-to-be-styled 42 between the heating surface 30 of theupper hair treatment portion 24 of the upper arm 12 and thehair-contacting portion 33 of compressible element 34 of the lowertreatment portion 26 of the lower arm 14. The stylist then closes thehair iron 10 by pressing on the upper and lower gripping portions 20 and22 of the upper and lower arms 12 and 14 until the arms are in thesubstantially parallel closed position. The stylist begins at the rootends 44 of the hair-to-be-styled 42 and proceeds to draw the hairthrough the iron 10 to the hair tips 46. Alternatively, rather than drawthe hair-to-be-styled 42 through the hair iron 10, the stylist my movethe iron 10 along the hair-to-be-styled 42 from the initial position atthe root ends 44 to an end position at the hair tips 46. The process ofdrawing the hair-to-be-styled 42 through the iron 10 may be repeatedseveral times until the hair 42 has achieved the desired degree ofstraightness or styling.

Advantages of the Present Invention

The present invention hair iron 10 provides distinct advantages over theprior art. By equipping the hair iron 10 with only a single heatingelement 28 on the upper arm 12, the present invention hair irondramatically reduces the heat load applied to the hair-to-be-styled 42and therein significantly reduces the risk of scorching or otherheat-related damage to the hair. Likewise, energy consumption is alsosignificantly reduced over prior art hair irons which feature heatingelements on each arm of the hair iron. By equipping the non-heated orlower arm 14 of the hair iron 10 with a compressible element 34 ratherthan a hard or rigid surface, the present hair iron 10 substantiallyreduces the likelihood of damage to the hair-to-be-styled 42 whichfrequently occurs when stylists over compress the hair by exerting toomuch force on the arms 12 and 14 of the iron 10. The compressibleelement 34 feature leads to significant reduction in the amount of bent,crushed, flattened, or kinked hair, as well as split ends. As mentionedabove, because both the compressive force and heat applied to thehair-to-be-styled is decreased, the present invention hair ironconsequently increases the fullness or volume of the hair.

The foregoing detailed description and appended drawings are intended asa description of the presently preferred embodiments of the inventionand are not intended to represent the only forms in which the presentinvention may be constructed and/or utilized. Those skilled in the artwill understand that modifications and alternative embodiments of thepresent invention which do not depart from the spirit and scope of theforegoing specification and drawings, and of the claims appended beloware possible and practical. It is intended that the claims cover allsuch modifications and alternative embodiments.

1. A hair iron comprising: first and second arms pivotally connected atone end, wherein the arms are able to move from an open position to aclosed position for the purpose of gripping hair; the first arm having aheating element integral with the first arm and disposed along its freeend; and the second arm having a non-heated compressible elementintegral with the second arm and disposed along its free end.
 2. Thehair iron of claim 1, further comprising a biasing spring adjacent thepivot and connected to the first and second arms such that the arms arebiased to a normally open rest position at an acute angle.
 3. The hairiron of claim 1, wherein when the first and second arms are closed theyare substantially parallel.
 4. The hair iron of claim 1, wherein whenheating element comprises a PTC-type heater.
 5. The hair iron of claim1, wherein the heating element comprises a hair-contacting heatingsurface that is coated with a material containing tourmaline.
 6. Thehair iron of claim 1, wherein the non-heated compressible element has ahair-contacting portion that is substantially flat.
 7. The hair iron ofclaim 1, wherein the non-heated compressible element comprises ahair-contacting portion having a pattern of peaks and valleys.
 8. Thehair iron of claim 7, wherein the depth from peak-to-valley of thepattern of the alternating surfaces is approximately 0.05 inch to 0.100inch.
 9. The hair iron of claim 8, wherein the compressible element ismade from a material selected from the group consisting ofpolytetrafluoroethylene, aramid fibers, polytetrafluoroethylene blendedwith other materials, and aramid fibers blended with other materials.10. The hair iron of claim 1, wherein the heating element comprises oneor more floating plate-type heating elements.
 11. The hair iron of claim5, wherein the non-heated compressible element comprises ahair-contacting portion having a pattern of peaks and valleys.
 12. Ahair iron comprising: first and second arms pivotally connected at oneend, wherein the arms are able to move from an open position to a closedposition for the purpose of gripping hair; the first arm comprising aPTC-type heating element integral with the arm and disposed along itsfree end; the PTC-type heating element comprising a hair-contactingheating surface coated with a composition containing tourmaline; thesecond arm comprising a non-heated compressible element integral withthe arm and disposed along its free end; and the non-heated compressibleelement comprising a hair-contacting portion having a pattern of peaksand valleys.
 13. The hair iron of claim 12, further comprising a biasingspring adjacent the pivot and connected to the first and second armssuch that the arms are biased to a normally open rest position at anacute angle.
 14. The hair iron of claim 12, wherein when the first andsecond arms are closed they are substantially parallel.
 15. The hairiron of claim 12, wherein the depth from peak-to-valley of the patternof peaks and valleys is approximately 0.05 inch to 0.100 inch.
 16. Thehair iron of claim 12, wherein the compressible element is made from amaterial selected from the group consisting of polytetrafluoroethylene,aramid fibers, polytetrafluoroethylene blended with other materials, andaramid fibers blended with other materials.
 17. The hair iron of claim12, wherein the heating element comprises one or more floatingplate-type heating elements.
 18. A hair iron comprising: first andsecond arms pivotally connected at one end, wherein the arms are able tomove from an open position to a closed position for the purpose ofgripping hair; a biasing spring adjacent the pivot and connected to thefirst and second arms such that the arms are biased to a normally openrest position at an acute angle; wherein, when the first and second armsare closed they are substantially parallel; the first arm comprising aPTC-type heating element integral with the arm and disposed along itsfree end; the PTC-type heating element comprising a hair-contactingheating surface coated with a composition containing tourmaline; thesecond arm comprising a non-heated compressible element integral withthe arm and disposed along its free end; the non-heated compressibleelement including a hair-contacting portion having a pattern of peaksand valleys; and the pattern of peaks and valleys having a depth frompeak-to-valley of approximately 0.05 inch to 0.10 inch.
 19. The hairiron of claim 18, wherein the heating element is adjustable from zerodegrees to approximately 450 degrees Fahrenheit.
 20. The hair iron ofclaim 18, wherein the heating element automatically shuts-off afternon-use for a predetermined period of time.